Derivative Financial Instruments and Fair Value of Financial Instruments (Details)	3 Months Ended	12 Months Ended										3 Months Ended																																			3 Months Ended
	Mar. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2012 MXN	Mar. 31, 2013 2013 [Member]	Mar. 31, 2013 2013 [Member] MXN	Mar. 31, 2013 2014 [Member]	Mar. 31, 2013 2014 [Member] MXN	Mar. 31, 2013 Derivative Instruments Settle in Year 2014 Member [Member]	Mar. 31, 2013 Derivative Instruments Settle in Year 2014 Member [Member] MXN	Mar. 31, 2013 Thereafter [Member]	Mar. 31, 2013 Thereafter [Member] MXN	Mar. 31, 2013 Franco-Nevada warrant [Member] USD ($)	Mar. 31, 2012 Franco-Nevada warrant [Member] USD ($)	Mar. 31, 2013 Palmarejo gold production royalty [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Palmarejo gold production royalty [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Palmarejo gold production royalty [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Palmarejo gold production royalty [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Mexican peso forward purchase contracts [Member] 2013 [Member] USD ($)	Mar. 31, 2013 Mexican peso forward purchase contracts [Member] 2014 [Member] USD ($)	Mar. 31, 2013 Mexican peso forward purchase contracts [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($)	Mar. 31, 2013 Mexican peso forward purchase contracts [Member] Thereafter [Member] USD ($)	Mar. 31, 2013 Mexican Peso Notional Amount [Member] 2013 [Member] oz	Mar. 31, 2013 Mexican Peso Notional Amount [Member] 2014 [Member] oz	Mar. 31, 2013 Mexican Peso Notional Amount [Member] Derivative Instruments Settle in Year 2014 Member [Member] oz	Mar. 31, 2013 Mexican Peso Notional Amount [Member] Thereafter [Member] oz	Mar. 31, 2013 Silver ounces received from Mandalay [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Silver ounces received from Mandalay [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Silver ounces received from Mandalay [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Silver ounces received from Mandalay [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Silver concentrate sales agreements [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Silver concentrate sales agreements [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Silver concentrate sales agreements [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Silver concentrate sales agreements [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Gold concentrates sales agreements [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Gold concentrates sales agreements [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Gold concentrates sales agreements [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Gold concentrates sales agreements [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Gold put options purchased [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Gold put options purchased [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Gold put options purchased [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Gold put options purchased [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Gold call options sold [Member]	Mar. 31, 2013 Gold call options sold [Member] 2013 [Member] USD ($) oz	Mar. 31, 2013 Gold call options sold [Member] 2014 [Member] USD ($) oz	Mar. 31, 2013 Gold call options sold [Member] Derivative Instruments Settle in Year 2014 Member [Member] USD ($) oz	Mar. 31, 2013 Gold call options sold [Member] Thereafter [Member] USD ($) oz	Mar. 31, 2013 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)	Mar. 31, 2012 Foreign Exchange Forward [Member] Mexican peso forward purchase contracts [Member] USD ($)
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net																																															$ 700,000	$ 2,700,000
Derivative Instruments, Loss Recognized in Income												9,100,000	13,200,000
Derivative instruments Settlement
Derivative, Notional Amount														21,297,000	24,895,000	24,691,000	20,766,000									100,000,000	0	0	0	4,395,000	0	0	0	25,683,000	0	0	0	1,260,000	720,000	0	0		0	720,000	0	0
Derivative average gold price in excess of minimum contractual Deduction Rate	400													502,000	498,000	494,000	490,000
Fair value of foreign exchange contracts																		29,400,000	0	0	0
Average rate			13.11		12.91		0.00		0		0
Average forward price																										1.00	0	0	0
Derivative average price																										29.72	0	0	0					1,637	0	0	0
Average strike price				2,000	2,000	1,934	1,934	2,000	2,000	0	0																											931	979	1,010	0	2,000.00
Notional ounces														42,433	50,004	50,004	42,409					379,422	0	0	0	100,000	0	0	0	147,898	0	0	0	15,685	0	0	0	32,500	47,000	30,000	0		15,000	47,000	30,000	0
Derivative Instruments, Gain (Loss) Recognized in Income, Net																																															600,000	800,000
Weighted Average Put Feature of Each Collar	$ 973.14	$ 967.86